Please note: This information was current at the time of publication. But medical information is always changing, and some information given here may be out of date. For regularly updated information on a variety of health topics, please visit familydoctor.org, the AAFP patient education website.

Information from Your Family Doctor

Onychomycosis (Nail Fungus)

What is onychomycosis?

Onychomycosis (ON-i-ko-my-KO-sis) is an infection in your toenails or fingernails that is caused by a fungus.

Why did I get it?

Doctors don't always know why. It is more common in people who have diabetes and other medical problems, and in older adults.

What can I do about it?

There are many treatments. None of them work all the time.

Your doctor can give you pills to kill the fungus. They work better than other treatments. But you need to take them every day for several months. You will have to have blood tests to check for side effects.

If you have fungus on only half of one nail, special nail polishes can sometimes kill the fungus. There are also treatments that use lasers and special lights to kill the fungus. These are new treatments, and doctors don't know yet how well they work. Most health insurance plans won't pay for them.

Here are some things you can do to lower the chance of getting more fungus on your nails:

Dry your feet with a towel and hair dryer after bathing.

Wear sandals or shoes made of real leather. Don't wear shoes made of rubber, plastics, or man-made materials.

Wear socks made out material that absorbs moisture, such as merino wool, nylon, or polypropylene. Don't wear cotton socks.

Use antifungal sprays or powders in your shoes. You can buy these at drugstores without a prescription.

Don't go barefoot in public showers.

Don't use nail polish or nail extenders, such as acrylic or gel nails. If you get manicures and pedicures, go to salons you trust, or bring your own tools.